textproduct: Quad Cities

KEY MESSAGES

- Dangerous heat continues through 7 PM this evening, with peak heat indices of 100 to 110 degrees. Extreme heat warnings and heat advisories are in effect.

- After a brief reprieve, heat and humidity will return on Tuesday and Wednesday. The overall pattern has a 55-70% probability of above normal temperatures through mid- September.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 205 AM CDT Sat Sep 5 2026

A widespread area of fog can be seen just to our northeast across central Wisconsin early this morning on satellite imagery. Mostly clear skies and light, variable winds across southwest Wisconsin, eastern Iowa, and northwest Illinois will allow this fog to continue developing as far south as the Highway 20 corridor through this morning.

Yet another hot and humid day is in store for areas along and south of Highway 30 today. Along and south of an Iowa City to Aledo line, heat indices of 100 degrees or more are likely (50-90%), while lower chances of exceedance (20-50%) are possible along the Highway 30- Interstate 80 corridor. No changes have been made to the Extreme Heat Warning or Heat Advisory, which are in effect through 7 PM this evening.

A reprieve from the heat, though brief, will arrive this afternoon and evening as a cold front drifts southward across the CWA. While it won't offer much relief during peak heating hours, the cooler and drier air will allow lows overnight to drop into the 60s, which will be the first time in 5 days for much of the area. Due to this, the Extreme Heat Warning and Heat Advisory will remain in effect through 7 PM this evening.

With this front moving through, it is possible that interactions with lingering outflow boundaries could produce isolated storms, though these probabilities remain low (<10%). The most likely scenario is that most, if not all, locations remain dry. If any storms were to develop, low shear would keep any severe potential at bay.

Sunday, cooler and drier weather is in store with highs in the 80s and lows in the 60s. After several days of heat indices above 100, this will feel quite pleasant for the holiday weekend.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 205 AM CDT Sat Sep 5 2026

Dry and seasonally warm conditions will continue through the remainder of the holiday weekend before the upper level ridge begins building back into the area. While LREF probabilities of heat indices greater than 100 degrees are low (10-20%), high temperatures on Tuesday will be around 5-10 degrees above normal. These high temperatures will continue on Wednesday, though there is some uncertainty due to the potential for a front to move through the area Tuesday night into Wednesday morning, bringing in rain and lingering cloud cover that could temper highs on Wednesday.

Wednesday night into Thursday, another boundary will sweep through the area. Much of guidance keeps this boundary dry, owing in part to the frontal passage on Wednesday sweeping out some of the moisture. As northwest flow returns to the region, near-normal temperatures will return through the end of the work week.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1242 AM CDT Sat Sep 5 2026

VFR conditions will prevail at all terminals but DBQ, where fog will result in MVFR to possibly IFR conditions. Light and variable winds and mostly clear skies are present across all terminals. This environment will support the development of fog at DBQ, which will lead to MVFR VSBYs in the 05/08-13Z period. It is possible conditions deteriorate further to IFR VSBYs of 1 to 1 1/2 SM, though any mention of IFR has been kept from this issuance due to low probability (20-30%). Otherwise, pleasant VFR conditions will be in place through the daytime hours, with winds 5-10kts from the north- northeast.

CLIMATE

Issued at 558 AM CDT Thu Sep 3 2026

The Quad Cities (MLI) has had two days to start this month with 95 degree highs. If a third happens today, it would be the longest such stretch in September since September 4-6, 1990.

Record Warm Low Temperatures:

September 3: KDBQ: 73/1939 KMLI: 76/1939

September 4: KDBQ: 71/1912 KMLI: 74/2018

September 5: KDBQ: 76/1881 KMLI: 76/1925

DVN WATCHES/WARNINGS/ADVISORIES

IA...Heat Advisory until 7 PM CDT this evening for IAZ040-051>053- 066. Extreme Heat Warning until 7 PM CDT this evening for IAZ063>065-067-068-076>078-087>089-098-099. IL...Heat Advisory until 7 PM CDT this evening for ILZ009. Extreme Heat Warning until 7 PM CDT this evening for ILZ015>018-024>026-034-035. MO...Extreme Heat Warning until 7 PM CDT this evening for MOZ009- 010.